Russian state-run media behemoth Rossia Segodnya's interview with a former leader of pro-Russian separatists in eastern Ukraine was edited to remove references to his work in Russia's Federal Security Service (FSB) and chaos among the rebels, his interviewer says.

Igor Girkin, known as "Strelkov," said in the interview that he is an "FSB colonel" and that rebel commanders in eastern Ukraine "were fighting with one another," according to a transcript published by interviewer Aleksandr Chalenko.

The redacted version of the interview published on December 1 by Rossia Segodnya omits both comments.

Chalenko said in a Facebook post that the text was edited by Girkin's press secretary and trimmed by Rossia Segodnya editors in a standard journalistic process.

Girkin, who held various posts in rebel regions of eastern Ukraine, had said previously that he served as a lieutenant colonel in the FSB -- the same rank Russian President Vladimir Putin held in the Soviet KGB -- until March 2013.

Russia denies that it lends military support to the separatists in eastern Ukraine.

Moscow has admitted that Russian servicemen have traveled to Ukraine to fight alongside the separatists but claims they are volunteers and were not deployed to the region by Russia.

Girkin was arguably the most prominent leader of the pro-Russian separatists and accused of war crimes by the Ukrainian government, which called him a Russian agent tasked with fueling violent unrest in the region.

"I am indeed an FSB colonel," Girkin, who resigned as a rebel commander in August amid reports that he had been wounded in battle, told Chalenko in the interview.

Russian President Vladimir Putin held the lower rank of lieutenant colonel in the Soviet KGB, the FSB's predecessor.

Other parts of the interview omitted in the Rossia Segodnya version included Girkin's description of the rebels' attempts to seize control of the Donetsk airport as "pointless" and "harmful" to the separatists.

Fighting between Ukrainian forces and the rebels over control of the airport has raged since May, resulting in hundreds of casualties.

Kyiv has accused Russian special forces of involvement in the separatists' push to take the airport in separatist-controlled Donetsk.

Established last December, Rossia Segodnya integrated the state news agency RIA Novosti and state radio station Voice of Russia into a single media conglomerate in what is widely seen as a Kremlin bid to tighten its control of Russia's media landscape.

Putin tapped controversial pro-Kremlin news anchor Dmitry Kiselyov, who has gained international notoriety for his bombastic criticism of the West and virulent antigay views, to oversee the new conglomerate.

On his Facebook page, Chalenko dismissed suggestions that his original interview was redacted by Girkin's representatives and Rossia Segodnya editors to bring it in line with the narrative of the Ukraine conflict pushed by the Kremlin.

He said his editors were limited by space constraints but that they granted him permission to publish the entire transcript at the Russian-language news portal Politnavigator.net "without hiding behind some pseudonym."